So it's clear there's a decent amount of aluminum raining down on us, what measures can be taken to enhance excretion, and attenuate further absorption?

IV Ca-EDTA is overall infeasible. I don't know of any effective oral / sublingual approaches. That leaves upregulation of processes that potentiate Al dissociation. The issue then remains increasing the odds it ends up going down an excretion pathway, rather than being stored somewhere else.